Study On The Mix Technology Of Low-Carbon For HPC Based On The Low Cement Clinker

The mix technology of low-carbon for High Performance Concrete（HPC）based on thelow cement clinker is that we should considering these factors of the durability, economy andas much as possible to reduce the amount of the cement clinker in the conditions of theconcrete strength and workability required. Because it could be directly to reduce the amountof coal consumption and the limestone raw material dosage in the cement production. Inaddition, the content of the cement clinker could be indirectly reduced with the reduction ofcement content in concrete. When we manufactured cement or concrete, the variety ofindustrial sludge or solid waste contents were relative increased due to the reduction of theclinker or the cement quantity. In this way, the environment pollution and the energyconsumption could be reduced.The innovations of this article were as follows: the influences of the grinding aids on thetypes of cement with the different amount of the clinker and the concrete performance, thecompatibility of the cementing material systems (cement clinker, admixture, mineraladmixture) with the water reducer, the mix proportion design method of the concretecombined with the overall calculation method of the high performance concrete proportiondesign and the specification for mix proportion design of ordinary concrete (JGJ55-2011)wereresearched. The carbon emissions of HPC based on the low cement clinker were calculated,and the methods of calculation covered the cement chemistry, the superimposed effect of thetypes of cement and the admixture proportion.In this article, the influence of additive on the cementing material of HPC was studied,and the concrete workability, strength, elastic modulus and chloride diffusion coefficient wereresearched. The concrete was composed with the components of a different proportion. Thetest results showed that：1) The strength grade requirements were not affected by the cement grinding aids, theproblem was that a best addition ratio was existed with the mixing quantity of the grindingaids. The adaptability of the same type grinding aids was different to the cement with differentamount clinker. The good compatibility of the cementing material systems with the waterreducer was existed, and the cementing material systems (including40%mineraladmixtures) was formed of the P.O42.5R consists of the ratio of0.016%grinding aids. But thecompatibility was not good when the cementing material systems (including20%mineraladmixtures) was formed of the P.O42.5R consists of the ratio of0.02%grinding aids, although the strength of P.O42.5R was improved. At the time of the compound proportion ofthe slag powder and the fly ash is too large (4:6), no matter any types cement was used thecompatibility could be affected.2) The good workability was shown and the required strength was fit by nine groupsconcrete mixed. The initial slump, the28days compressive strength was suitable for180±20mm,≥C60.1hour slump loss was increasing with the initial slump of concreteincreasing. The double mixing technology of the high performance concrete was used to meetthe requirements of the workability under the reasonable mix proportion whether includingthe grinding aids mixed into the types of cement with the different clinker ratio. Water-binderratio was the key factor to affect the strength of concrete mixed by P.II42.5R and P.O42.5R.3) With the increase of admixture,and the clinker-binder ratio of the concrete decreasing,the increasing regularities of the28days strength and the concrete elastic modulus were allshown to the concrete mixed with P.O42.5R and P.II42.5R, but it was the opposite to theconcrete mixed with P.S.B42.5.4) With the mineral admixture mix proportion gradually increasing in the concrete mixedby the cement of three different clinker content, the chloride diffusion coefficient wasgradually decreased, then the corresponding water-binder ratio was minimum; In addition,with the growth of the60days strength of the concrete mixed by three types of cement, theconcrete clinker-binder ratio was reduced gradually, as well as the chloride diffusioncoefficient.Through the analysis of the concrete CO2emissions, cost, integrated performance andthe value coefficient, the results showed that the CO2emissions of the experimental group9was the least and the total efficacy coefficient was the largest,but the cost of the mixproportion of the experimental group6was the least, the value coefficien（tEqual to the ratioof the total efficacy coefficient and the cost coefficient）was the largest. Therefore, the mixproportion of the experimental group6was the optimum proportion, that the total amount ofcementing material was535.33Kg, P.O42.5R (consists of the content0.016%of the grindingaids) was the proportion of60%, the percentage of mineral admixtures was40%, thecompound proportion of slag powder and the fly ash was2:8, the water reducer ratio was1.52%, and sand ratio37%.